RMSF is transmitted to humans through the bite of infected ticks. The primary vectors in the United States are the American dog tick (Dermacentor variabilis), the Rocky Mountain wood tick (Dermacentor andersoni), and the brown dog tick (Rhipicephalus sanguineus), particularly in the southwestern states.

Rocky Mountain Spotted Fever

Rocky Mountain spotted fever (RMSF) is a severe and potentially life-threatening tick-borne illness caused by the bacterium Rickettsia rickettsii. First identified in the Rocky Mountains,…